scholarly journals Monitoring standard and extended half‐life products in hemophilia: Assay discrepancies for factor VIII and IX in pre‐ and postinfusion samples

2020 ◽  
Vol 4 (7) ◽  
pp. 1114-1120
Author(s):  
Cecilia Augustsson ◽  
Eva Norström ◽  
Nadine Gretenkort Andersson ◽  
Eva Zetterberg ◽  
Jan Astermark ◽  
...  
Keyword(s):  
Factor Viii ◽  
Half Life ◽  
Viii And Ix

Role of enhanced half-life factor VIII and IX in the treatment of haemophilia

2015 ◽  
Vol 169 (6) ◽  
pp. 768-776 ◽  
Author(s):  
Ali J. Mahdi ◽  
Samya G. Obaji ◽  
Peter W. Collins
Keyword(s):  
Factor Viii ◽  
Half Life ◽  
Viii And Ix ◽  
Life Factor

scholarly journals A Method for Deriving Pharmacokinetic Constants for Factor VIII and IX from Limited Blood Sampling

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3501-3501 ◽  
Author(s):  
Miguel Antonio Escobar ◽  
Daniel Preston Bond ◽  
Madeline Cantini ◽  
Krishna Cannon
Keyword(s):  
Factor Viii ◽  
Half Life ◽  
Research Funding ◽  
Decay Constant ◽  
Hemophilia A ◽  
Health Science ◽  
Blood Sampling ◽  
Population Pharmacokinetic ◽  
Viii And Ix ◽  
Trough Levels

Abstract Introduction The treatment of hemophilia A and B is based on the replacement of the deficient factor dosed by weight. However, dosing for hemophilia treatment has been arrived at by empiric assessment, essentially "trial and error" based on the pharmacokinetics (PK) of the factors and the characteristics of the replacement product. In the last decade clinical pharmacokinetics has gained popularity in hemophilia so that factor dosage can be adjusted according to the requirement of the individual patient. Factor-specific population pharmacokinetic models have been developed for individualized treatment of patients with hemophilia A and B. The math modeling technique presented in this project relies on minimal blood sampling to derive the constants necessary to predict the peak and trough levels within the commonly excepted error bounds. Methods Data that included FVIII, FIX levels and weight were obtained retrospectively from severe hemophilia A and B adult patients and approved by the ethics committee of the University of Texas Health Science Center. A single compartment decay model equation was used in both a custom iOS application and an Excel spreadsheet to calculate the decay constant between any 2 points on a decay curve. Using this local constant as the half-life in the standard decay equation allowed the calculation of the peak at time = 0. This peak combined with dosing information and the subject's weight allowed the calculation of the Recovery. These 2 constants in the equation: Level=(dose*Recovery/weight)*0.5^(time/half-life) allowed the calculation of the level at any point on the curve. Using this method on several example datasets showed that the model is reasonably able to predict peak and trough levels for both factor VIII and IX. Because of the time dependent nature of the local decay constant, better results are obtained using data points after the first half of the expected half-life. This method can also be used to predict steady state levels, peaks and troughs for any prophylaxis schedule. Conclusion Appropriate dosing of factor VIII or IX is at best an approximate calculation. The method described in this publication generates a math model that is generally as accurate as a multiple sample PK study with far fewer blood samples taken. Clinical applications of this model can be utilized to predict factor levels after a single infusion of factor VIII/IX in adults that are treated on-demand or prophylaxis. It can also be utilized in individuals that are infusing extended half-life products or in the surgical setting. Disclosures Escobar: Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Bond:Pfizer: Consultancy, Research Funding. Cantini:Pfizer: Research Funding. Cannon:Pfizer: Research Funding.

scholarly journals Modeling The Impact of Potential Differences In Real-Wolrd Adherence With Extended-Half-Life Vs. Conventional Factor Viii And Ix on Bleeding

2015 ◽  
Vol 18 (7) ◽  
pp. A660-A661
Author(s):  
A Iorio ◽  
S Krishnan ◽  
K Myrén ◽  
S Lethagen ◽  
N McCormick ◽  
...  
Keyword(s):  
Factor Viii ◽  
Half Life ◽  
Viii And Ix ◽  
The Impact

The diagnosis and management of factor VIII and IX inhibitors: a guideline from the UK Haemophilia Centre Doctors' Organization (UKHCDO)

2000 ◽  
Vol 111 (1) ◽  
pp. 78-90 ◽  
Author(s):  
C. R. M. Hay ◽  
T. P. Baglin ◽  
P. W. Collins ◽  
F. G. H. Hill ◽  
D. M. Keeling
Keyword(s):  
Factor Viii ◽  
Diagnosis And Management ◽  
Viii And Ix ◽  
The Uk

Hepatitis C and Pasteurised Factor VIII and IX Concentrates

1995 ◽  
Vol 73 (04) ◽  
pp. 736-737 ◽  
Author(s):  
D Klarmann ◽  
W Kreuz ◽  
G Auerswald ◽  
K Auberger ◽  
H Rabenau ◽  
...  
Keyword(s):  
Hepatitis C ◽  
Factor Viii ◽  
Viii And Ix
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